Allergic Living » cat allergyhttp://allergicliving.com
The magazine for those living with food allergies, celiac disease, asthma and pollen allergies.Fri, 09 Dec 2016 15:04:48 +0000en-UShourly1http://wordpress.org/?v=4.3.1Cat Allergy Therapy Fails in Crucial Studyhttp://allergicliving.com/2016/08/23/cat-allergy-therapy-fails-in-crucial-study/
http://allergicliving.com/2016/08/23/cat-allergy-therapy-fails-in-crucial-study/#commentsTue, 23 Aug 2016 13:45:54 +0000http://allergicliving.com/?p=42624The fate of a much-heralded cat allergy therapy, Cat-SPIRE, is uncertain after a late-stage clinical trial showed a placebo was just as effective as the treatment.

“I was very disappointed,” says allergist Dr. Harold Nelson of the National Jewish Medical and Research Center in Denver, who helped head the international research effort.

With the immunotherapy treatment, the British biotech firm Circassia Ltd. aimed to reduce the number of allergy shots needed to desensitize a patient to cat allergies from about 100 over three years with traditional allergy shots to four shots over four months by using fragments, or peptides, of the offending Fel d1 cat protein.

About 1,400 patients in the U.S., Canada and Europe between the ages of 12 and 65 who stiffer from an allergy to cat dander enrolled in the phase 3 clinical trial.

It’s not known why the research for the short-course therapy would have reached such an advanced stage before its shortcomings came to light. However, Nelson says “a failed study was always a good possibility because of the many variables in patients’ perennial rhinitis symptoms that don’t relate to cat allergy.” These could be anything from seasonal allergies to a sensitivity to dust mites.

He also says it’s possible that subjects with cat allergies were the wrong people to study with the peptide technology because they may have already acquired a high degree of tolerance due to chronic feline exposure.

Allergic Living’s attempts to reach Steve Harris, Circassia’s chief executive, or get a comment from the company, were unsuccessful. However, in a news release, Harris expressed surprise and disappointment in the results.

“We will now rapidly analyze the full dataset, address the implications for our wider allergy pipeline and provide an update on the development plans for our broader business at our interim result,” he said. “At the same time, we will continue to focus resolutely on our wider portfolio.”

But while the results were bad news for investors – Circassia’s stock plunged 64 percent on the news – it’s not clear what the failed study means for those with allergies.

Current studies of peptide-based shots for birch and dust mite allergies will continue. “The results should be available within the coming year, and will tell us if the peptide approach is valid,” says Nelson.

Meanwhile, the company has halted the development of related grass and ragweed peptide therapies, and plans to “work with external experts to understand whether any confounding factors affected the results.”

This article first appeared in Allergic Living magazine. See the newer article on the therapy failing in a crucial study here.

THE ANCIENT Egyptians were said to revere the cat, glorifying it in hieroglyphs, depictions of deities and artwork. While today’s domestic kitty may not enjoy the same royal treatment, the feline still wields serious power: just being in the same room as one can trigger itching, coughing, wheezing and even a full-on asthma attack in the millions who have cat allergy.

The American Academy of Allergy, Asthma and Immunology says the condition affects an estimated 50 million Americans, including the 30 percent of those with allergic asthma who list cat dander as a key trigger.

Other than simply avoiding cats, immunotherapy, or allergy shots, is the only current treatment option for this allergy. The idea here is to re-train the immune system to accept the cat’s allergy-inducing protein rather than react to it as a dangerous invader.

To do so, the doctor injects small amounts of cat protein extract into the body over several visits, slowly increasing the dosage and then staying at a target level for three to five years. The hope is to achieve desensitization, or at the very least, greatly reduced symptoms.

The process is far from ideal. Not only does it require close to 100 injections, it is incredibly time-consuming, with untold hours spent at the doctor’s office. Not surprisingly, many patients simply quit going. Immunotherapy also always carries a reasonable risk of reaction, since the very thing a person is allergic to is being injected into the body. Anaphylaxis to immunotherapy, while uncommon, certainly has been reported, which is why patients are meant to wait at least half an hour in the doctor’s office after receiving an injection.

This is all that’s available today. However, the big news in the allergy and asthma research community is that a new, quick, and seemingly effective treatment for cat allergy looms large on the horizon, holding the promise of an end to the widespread grief.

Reports from a recently completed clinical trial speak for themselves. After just four shots of the new product – named Cat-SPIRE – patients experienced a significant decrease in symptoms when exposed to cat allergens. Not four shots per month or year, but just four shots in total, each taken one month apart. Two years later, the results were largely the same.

“That took us all by surprise,” says Mark Larché, an immunologist and professor of medicine at McMaster University in Hamilton, Canada. “To get a two-year effect after just one course of treatment, particularly when it’s only four injections, that’s very encouraging.” Larché is the co-founder of Circassia Ltd., a British biotech firm that is spearheading the product’s development along with the Canadian company Adiga Life Sciences, which is jointly owned by Circassia and McMaster University.

The key to Cat-SPIRE is the science behind the shot. Circassia scientists take the allergenic cat protein, called Fel d1, and break it down into basic parts called peptides. The building blocks of proteins are called amino acids, and peptides are strings of two or more amino acids. The Fel d1 protein is normally 162 amino acids long, while Cat-SPIRE contains seven synthetic peptides, each 15 amino acids in length, and each hand-picked to generate the desired response.

“Currently available immunotherapy basically takes the thing you’re allergic to and injects it into you,” says Steve Harris, CEO of Circassia and director of Adiga Life Sciences. Cat-SPIRE, he explains, was created by zeroing in on parts of Fel d1 that promote a regulatory, or non-allergic, immune response. By using fragments of Fel d1 created in a lab as opposed to the entire protein, fewer shots are needed, reactivity is lessened, increases in dosage are not required, and so far, the results have been impressive.

Patients have now been recruited for a final (or phase 3) trial that will confirm the shot’s effectiveness and also test whether giving eight injections instead of four makes any difference. About 1,400 cat-allergic individuals between the ages of 12 and 65 have enrolled in the trial, which is taking place in multiple sites across the United States, Canada and Russia over the next year.

Yet researchers already know that the shot won’t be equally effective for everyone. Dr. Harold Nelson, the principal investigator of the phase 3 trial, is quick to point out that patients in the previous trial showed an average symptom reduction of 50 percent. This suggests that Cat-SPIRE probably has a strong effect for many individuals, while others will likely benefit to a lesser degree.

Air Canada will not be required to provide special accommodations for those with dog allergies, according to a recent decision by the Canadian Federal Court of Appeal.

The appeal follows a 2013 ruling by the Canadian Transportation Agency that mandated that the airline create a five-seat buffer zone between pet or service dogs and those with severe canine allergies. That CTA ruling also said that if a dog-allergic passenger was flying on an aircraft that did not have a High Efficiency Particulate Air (HEPA) filter or provide completely unrecirculated fresh air, dogs would be banned for that flight.

These were essentially the same regulations that the CTA applied to people allergic to cats in a decision in 2012.

However, the appeal court found the CTA ruling did not adequately consider Air Canada’s argument that cat dander stays airborne longer than that of dogs and given these inherent differences between the two allergens, the same rules and accommodations do not need to be made for those with dog allergies.

Air Canada further contended the new regulations would cause discrimination against those with service dogs.

“I have no hesitation in saying that common sense has not prevailed in the present matter,” wrote Justice Marc Nadon, one of the three judges on the deciding panel. “The agency determined important issues, not only for the applicant and all those having dog allergies, but also for Air Canada …. Had common sense prevailed, one would have expected the agency, at some point in time, to realize that it was disposing of these important issues without, in effect, the full participation of Air Canada.”

WestJet, another major Canadian airline, notes in their allergy policy that they will create a buffer zone of five rows between passengers carrying cats and those with cat allergies, as long as they are notified of the allergies at least 48 hours prior to travel. Dogs, small birds, and rabbits are also allowed to be carried on board, but the buffer zone policy does not apply to other pet allergies.

Asthma organizations were dismayed by the ruling and the Air Canada’s decision to appeal. “We are disappointed that Air Canada decided to put the needs of pets and their owners over the health and safety of passengers with a severe allergic disability,” said Rob Oliphant, president of the Asthma Society of Canada (about 80 percent of asthma is allergy-based and exposure to pet dander is a common trigger). “At a time when accommodation for people with disabilities in Canada is becoming more commonplace, Air Canada is taking a step backwards and putting their passengers at risk,” he said.

This appeal court ruling is also at odds with recommendations from the association representing Canada’s doctors. “The Canadian Medical Association recommends a ban on all pets, except for certified service animals, travelling inside the aircraft cabin on all Canadian passenger planes,” says a resolution from the association’s 2011 annual meeting.

]]>http://allergicliving.com/2015/02/17/air-canada-cuts-dog-allergy-accommodations/feed/0Child’s Best Friend: The Dog Unleashed as the Surprising Allergy Preventerhttp://allergicliving.com/2015/01/22/childs-best-friend-the-dog-unleashed-as-the-surprising-allergy-preventer/
http://allergicliving.com/2015/01/22/childs-best-friend-the-dog-unleashed-as-the-surprising-allergy-preventer/#commentsThu, 22 Jan 2015 13:50:15 +0000http://allergicliving.com/?p=32131Want to protect your child against allergies? Increasingly science is saying: get a dog, and get it early. -From Allergic Living magazine’s Winter 2014 edition.

PAMELA Phillips grew up with allergies but that didn’t stop her family from owning low-shedding dogs when she was younger. “I never really had allergies to our dogs,” she recalls. As an adult she and her husband got a cat and, a couple of years before their son Liam was born, they added a dog to the family. Things were going pretty well with Phillips’ allergies, until she got pregnant. Her eczema flared and, at the same time, she found herself too tired to take care of the dog properly. Her mother-in-law took the German shepherd-cross as a way to help out temporarily.

Then shortly after Liam was born, Phillips started having asthma attacks. The new mother would wake up at night struggling to breathe. (She saw an allergist who prescribed asthma medication.) Meanwhile, young Liam began to show signs of eczema. When her mother-in-law asked if she could keep the dog, it suddenly seemed a good idea, since the Phillips feared that her son’s allergies would get worse. The couple, who live in a suburb of Nashville, also found a new home for the cat.

Phillips’ thinking is in line with the advice doctors have given out for years: if your family has a history of allergies, you should not expose your baby to pets and their allergenic dander. But what scientists thought they knew about early exposures to things that are allergenic is being turned on its head. Evidence has been amassing in recent years to point to one startling fact: having a dog around a baby in its early life can actually prevent allergies from developing.

In 2011, for instance, researchers at the Henry Ford Hospital in Detroit drew illuminating findings from their long-running Childhood Allergy Study. They showed that, at least for boys, being exposed to a dog in the first year of life reduced the risk of being sensitized to dogs 18 years later by 50 percent. For girls it was less, but having a dog in the house as an infant still made them 33 percent less likely to have an allergy to dogs going into adulthood than those who did not live with a dog.

This “dog protective effect” doesn’t just apply to animal allergies, but to the spectrum of allergic conditions as a whole, from hay fever to eczema, asthma and even food allergies. Many leading scientists are now so certain of this effect that they are moving past “whether” it happens to “why” it happens.

What is it about dogs that turns them into magical protectors of their young owners, helping them to escape allergies? Not only that, but what does this mean for people who are having children today?

***

ONE OF THE EARLY inklings that dogs somehow play a role in stopping kids from becoming allergic emanated from the Childhood Allergy Study. It was 2002, and the authors were analyzing data of almost 500 Detroit children, whom they had followed from infancy until 6 or 7 years of age. “We had actually collected information about animals in the house because we thought it would increase the risk,” says Christine Cole Johnson, a lead author of the study and chair of Henry Ford’s department of public health sciences.

Instead, it turned out that the children in the study growing up with pets, and in particular, dogs, had lower IgE (or immunoglobulin E, the antibody involved in allergies) to dogs and cats – and also to pollen, dust mites and mold. “They had lower IgE to everything,” says Johnson. “It seemed like a general effect.”

Then in 2009, a paper published from another long-term population study – this time out of Dunedin, New Zealand – showed a similar result. In research that followed more than 1,000 people from birth to age 32, scientists found that living with a dog and a cat (cats are more popular as pets in New Zealand than dogs) lowered the chances that a person developed allergies, and this lasted well into adulthood.

Dr. Malcolm Sears, an epidemiologist, respiratory specialist and professor of medicine at McMaster University in Hamilton, Canada, is a consultant on the Dunedin study, which has been continuing for an astounding 41 years. He says one important thing they looked at in this study was whether parents who owned pets were less likely to be allergic themselves and therefore the children were at lower risk for developing allergies. Interestingly, he says: “That wasn’t the case.”

In fact, there have now been dozens of these “birth cohort” studies around the world that follow children from infancy in an attempt to unlock the mystery of what makes people develop asthma and allergies. Many have collected data on pets in the house, and in a study published in the Journal of Allergy and Clinical Immunology in 2013, researchers pooled the results of 21 such studies to determine whether exposure to pets in utero, during infancy or in childhood had any bearing on whether the child developed atopic dermatitis, or eczema. They looked at households that only had a dog, households that only had a cat, and households with both.

“Dogs alone gave a 30 percent reduction (in eczema) , cats alone was a 6 percent reduction, basically no effect. When they put all pets together, they again showed an effect of about a 25 percent reduction. So it’s really driven by dogs,” says Sears, who was not an author on the paper.

This, he adds, raises the intriguing questions: “What is it about owning a dog? Is it the dog itself, is it the dog allergen, is it the dirt the dog brings into the house? And that’s much less certain.”

Next: Baby, Dog and the Microbiome

]]>http://allergicliving.com/2015/01/22/childs-best-friend-the-dog-unleashed-as-the-surprising-allergy-preventer/feed/0Can Cat Allergy Develop in Adult Life?http://allergicliving.com/2013/07/16/can-cat-allergy-develop-in-adult-life/
http://allergicliving.com/2013/07/16/can-cat-allergy-develop-in-adult-life/#commentsTue, 16 Jul 2013 17:05:14 +0000http://allergicliving.com/?p=18400Q. My teenage daughter brought home (and we’ve adopted) a calico cat. I started getting a runny nose and a cough when near it, so I went to an allergist for testing. The results were positive. I don’t get it: our family had cats when I was a child. Can you develop an allergy to cats in your forties? Must we give him away?

Dr. Bassett: Yes, although allergies chiefly develop in children, adolescents and young adults, they can manifest during mid-adulthood.

However, the color and gender of your new cat could be to blame. I conducted a small, yet preliminary clinical study that identified a strong correlation of moderate to severe allergy symptoms with darker colored cats in a sensitive population of cat owners.

Additionally, I found that female cats produce less pet allergen than male cats.

Avoidance is the primary treatment, though this is not a popular choice for many pet lovers. Certainly portable HEPA air filtration and/or HEPA pleated filters in a home ventilation system (HVAC) can help to reduce the level of airborne pet allergens.

Additionally, an allergist can review your options if you have direct exposure to a home pet. These include environmental modification, medications and of course allergy injections, which serve to increase your tolerance to the cat allergens in your home.

Dr. Clifford Bassett, an allergist and asthma specialist, is the Medical Director of Allergy & Asthma Care of New York (www.allergyreliefnyc.com; Twitter @allergyreliefny). He is also on the faculty of NYU School of Medicine and Weill Cornell Medical College in New York City.

]]>http://allergicliving.com/2013/07/16/can-cat-allergy-develop-in-adult-life/feed/0New Cat Allergy Vaccine Set for Its Big Testhttp://allergicliving.com/2013/01/14/new-cat-allergy-vaccine-set-for-its-big-test/
http://allergicliving.com/2013/01/14/new-cat-allergy-vaccine-set-for-its-big-test/#commentsMon, 14 Jan 2013 20:04:03 +0000http://allergicliving.com/?p=15740Update: The results of the peptide trial in summer 2016 unfortunately proved unconvincing for this treatment. We have a full interview with Dr. Harold Nelson in the Fall 2016 issue of Allergic Living magazine.

A new study aims to take a huge leap forward against one of the most potent allergy and asthma triggers: the house cat. Up to 1,200 patients are enrolling in an international study to evaluate a new form of allergy immunotherapy which, if successful, will require as few as four allergy shots, given monthly, to rid a patient of an allergy to cat dander.

Current immunotherapy for cats takes about three years and often more than a hundred shots to complete.

“Use of immunotherapy has always been limited by the long treatment required,” said allergist Dr. Harold Nelson of National Jewish Health in Denver, who is heading the project. “If the current study confirms earlier findings, it could be a major step forward for allergy treatment,” he said in a news release.

With traditional allergy immunotherapy, multiple injections of protein triggers like cat dander or pollen are given in small then increasing amounts over a long period of time. The idea is to gradually build tolerance and, ultimately, to desensitize the patient to the allergen.

While this type of vaccination is currently the only way to treat the underlying allergic disease (rather than just allergy symptoms), it is a fairly invasive, costly and time-consuming, since patients must make numerous visits to the doctor.

Cat allergy is one of the most common allergic disorders, and a frequent trigger for asthma. The protein in cat dander that causes almost all symptoms is “fel d 1”, and the new vaccination therapy, called ToleroMune, works by injecting seven tiny protein fragments or “peptides” of this cat protein, as opposed to the whole protein.

By using the fragments, which aren’t large enough to provoke an allergic reaction, studies to date show that patients can become desensitized to cat much more rapidly and with far few side effects. Unlike the proteins used in traditional immunotherapy, as the protein fragments are not large enough to cause a reaction.

The study is expected to involve about 1,200 participants at National Jewish Health as well as at more than 100 centers in the United States, Canada, and Europe. Researchers hope to confirm earlier findings which showed that after four shots of ToleroMune, which has been developed by the British firm Circassia Ltd., many patients became desensitized and remained so a year later.

]]>http://allergicliving.com/2013/01/14/new-cat-allergy-vaccine-set-for-its-big-test/feed/0Dog and Cat Allergies Make Ragweed Worsehttp://allergicliving.com/2010/09/03/dog-and-cat-allergies-make-ragweed-worse/
http://allergicliving.com/2010/09/03/dog-and-cat-allergies-make-ragweed-worse/#commentsFri, 03 Sep 2010 13:48:42 +0000http://allergicliving.ds566.alentus.com/?p=5895Scientists are discovering that if you have year-round allergies, for example, dog, cat or dust mite allergies, you’ll be hit extra hard once ragweed season rolls along.

The study, which put 123 people with ragweed allergy in a specially-controlled room with their allergen for three hours, found that those who were also allergic to dogs, cats and dust mites developed symptoms faster, or experienced stronger symptoms, than those who didn’t have the other allergies.

However, the differences between the two groups lessened as the hours went on (they filled out questionnaires every 30 minutes) suggesting that once ragweed season is in full swing, everyone is affected equally.

Lead author of the study, Dr. Anne Ellis, and her team at Kingston General Hospital in Ontario suggest that to avoid this early, intense reaction, ragweed, allergy sufferers should treat their other allergies with immunotherapy or year-round allergy medication.

Another option is to limit exposure to dogs or cats leading up to ragweed season.

]]>http://allergicliving.com/2010/09/03/dog-and-cat-allergies-make-ragweed-worse/feed/1Non-Allergic Cat: Soon A Pet To Gethttp://allergicliving.com/2010/08/27/research-in-the-air/
http://allergicliving.com/2010/08/27/research-in-the-air/#commentsFri, 27 Aug 2010 22:12:22 +0000http://allergicliving.ds566.alentus.com/?p=2598From the Spring 2010 edition of the magazine: From the hypoallergenic cat to herbal tabs for asthma, to testing for allergy from birth, Allergic Living investigates what’s in the researchpipeline.

Idea: Hypoallergenic Cat

What’s Involved: Genetically engineering a cat that doesn’t have the gene that makes Fel d 1 protein, which causes the majority of allergic reaction. Once a colony of hypoallergenic cats is established, kittens could be bred using “traditional” methods.
Where We Stand: In 2006 a company called Allerca Inc. claimed to have bred the world’s first hypoallergenic kittens and Time magazine hailed them as one of the best inventions of the year.

But the company and its founder have been the subject of controversy, with the media and a dedicated website questioning whether the firm, now called Lifestyle Pets, really has sneeze-free cats.

But this is not the only company in the hunt for the hypoallergenic kitty. Dr. David Avner, an emergency room physician in Denver, has been working with molecular biologists on silencing the Fel d 1 gene for years, and so far has come up empty-handed.

In the summer of 2009, his team thought they had successfully knocked out the gene, which could lead to the breakthrough they’ve hoped for.

While Avner admits to being “optimistic” in predicting when his company, Felix Pets, will have cats on the market, he says there’s little doubt that in 10 years, a hypoallergenic cat will be in people’s homes.

“Without question, someone is going to do it. It’s too obvious an application of the technology, and the desire for people to have allergen-free cats is too high for it to go unrealized.”

Idea: Herbal Tablets for Asthma

What’s Involved: The Antiasthma Herbal Formula (ASHMI) is a tablet containing three traditional Chinese herbs. A study of patients in China shows it improves lung function and reduces use of bronchodilators.

Where We Stand: Dr. Xiu-Min Li at the Mount Sinai School of Medicine and her colleagues continue to study ASHMI in mice and people, comparing it to using corticosteroids. New, unpublished data show that eight weeks after mice stop taking the corticosteroids, their asthma symptoms return when they are exposed to triggers.

However, the mice on the herbal formula are still protected eight weeks later. Safety studies in humans have been completed, and Phase 2 efficacy studies are continuing.

One of the benefits to using ASHMI, instead of a steroid, is that there are fewer side effects, such as weight gain. However, Li says corticosteroids will be the standard treatment for asthma for years to come.

“The practical protocol will be to have a herbal remedy that will reduce the steroid’s side effects and help to maintain the protective effect,” she says.

Idea: Quick-Acting Allergy Shots

What’s Involved: Currently, immunotherapy to environmental allergies such as trees, grass, ragweed and cats, sometimes called allergy shots, requires numerous needles over several years. The shots also carry the risk of anaphylaxis in some individuals. Now, a few companies are developing therapies to make the treatment process far shorter and also safer.
Where We Stand: Swiss firm Cytos Biotechnology has developed a vaccine for environmental allergies that doesn’t use the allergen, but instead takes a virus-like particle that’s easily recognized by the immune system and stuffs it with a DNA sequence to stimulate the immune response.

The idea is to minimize side effects and the potential for anaphylaxis associated with current allergy shots.

To date, Cytos has found its shots to be effective for people with allergy symptoms from dust mite and cat allergies. Results are expected this spring from a study of patients with allergic asthma. The company hopes to partner with a leading pharmaceutical manufacturer once the studies are completed.

A U.K. company called Allergy Therapeutics has developed a modified form of immunotherapy to grass, ragweed, and tree pollen that it believes is effective after just four shots over three weeks. The company’s process involves chemically modifying natural allergens to make the vaccine safer to administer at higher doses.

The modified allergens are also supposed to be active for longer in the body, and are given along with an adjuvant that boosts the immune system’s response and encourages allergen tolerance. The company hopes to launch the “grass” versions of the vaccine in some European countries within the next two years.

Another U.K. company, Circassia, is in late-stage development of vaccines for ragweed, dust mites and cat allergy. These vaccines use small bits of the allergen, rather than a whole protein, lessening the risk of reaction to the shot.

The doctor’s advice sounds clear enough – if pets make you wheeze and sneeze, stay away. But anyone with animal allergies knows life isn’t always so simple.

Some people whose eyes are aflame after five minutes near a sheepdog can live with a poodle without ever cracking a tissue box. Others find that regularly bathing a pet greatly reduces allergic symptoms. But yet an unlucky few can react to dander inside a house where a cat hasn’t lived for years.

Who Reacts

Even our understanding of the prevalence of pet allergies is fuzzy. Although an estimated 20 to 30 per cent of young adults will react to at least one airborne allergen, studies have shown early exposure to animals (which researchers now suggest can have a protective effect), where you live, and whether you experience asthma, hay fever or both can all influence the development of allergies to animals.

Research from the U.S. National Institutes of Health shows that cats are the single biggest trigger for asthma, causing reactions in 29.3 per cent of asthmatics. A Swedish study, meantime, found 40 per cent of kids with asthma reacted to cats, 34 per cent to dogs, and 28 per cent to horses.

For the kids who got runny noses and itchy eyes, 49 per cent reacted to cats, 33 per cent to dogs, and 37 per cent to horses.

Dr. Jeffrey Davidson, an allergist in San Francisco and a clinical professor at the University of California San Francisco, says it’s fair to expect that as the incidence of allergic disease grows, so does the number of people reacting to animals. And while cat allergies are by far the most prevalent, people can be sensitized to any animals with feathers and fur, including dogs, guinea pigs, mice, birds, and ferrets.

The Symptoms

The range and severity of symptoms is vast, and includes itchy, runny nose and sneezing, irritated, watering eyes, wheezing and shortness of breath, eczema and hives. “Some people say they don’t have a problem unless they touch the pet and touch their eyes,” Davidson said. “And there are other people who walk into a room where there is a cat, or there has been one, and they will have an asthma attack.”

The Allergens

The culprits setting of these reactions are a series of proteins found in concentrated amounts in dander (flakes of dead skin), saliva and oil called sebum that hair follicles secrete to protect fur and skin. In some animals, allergenic proteins that originate in the blood are released through urine. The cat’s most prominent allergenic protein is called Fel d1, and its counterpart in dogs is Can f1.

Dr. James Ransom, an allergist in Topeka, Kansas and clinical instructor at The University of Kansas Medical Center, says cats’ constant grooming and indoor litter boxes mean these allergens are continuously evaporating into indoor air. A pet lover might reason a hairless cat or a short-haired dog should be fine. Not necessarily. Ransom says that, regardless of their fur, pets still emit the allergy-causing proteins from their skin, glands, dander, urine and saliva.

Plan B Solution

Ransom says if a patient has a severe reaction to animals or develops asthma, he’ll advise that the pet has to go. But “getting people to get rid of pets is very difficult.”

His Plan B is to tell the family to minimize the exposure. First, someone not allergic to the animal should wash it once a week. Next, the pet should never be allowed into the allergy sufferer’s bedroom. The pet’s roaming area in the house should be reduced to exclude areas where the allergic person spends much of his or her time.

Finally, cloth-covered furniture and carpeting (which Ransom calls the “reservoir of allergens”) must be replaced with leather or vinyl furniture and hard floors such as linoleum or tile.

Although some shampoos and sprays claim to reduce how much allergenic protein your pet totes around, Davidson says washing a pet with water alone is probably just as effective. Wipe down a cat with a damp cloth instead of bathing him, the specialist advises, to avoid “losing your forearms.”

The Cat Comes Back

Removing a pet may not be the end of the story. Cat and dog proteins are ubiquitous: one study found the proteins in 100 per cent of U.S. homes tested, though only 49 per cent actually housed a dog or cat.

Davidson explains that cat protein is dispersed in particles so small that some remain suspended instead of sinking to the ground. Enough protein to cause symptoms can be present for months, or even years after the cat has left the building.

After a pet has been removed, it’s time to get out the rubber gloves, and your wallet. Davidson says drapes, carpet and furniture should all be professionally steam cleaned, particularly if a cat was present, and removing carpets is worthwhile.

“All the dust in the room will contain a lot of cat protein,” he notes, stressing the need to get “onto the top of door jams and into light fixtures.” Ransom adds that if carpeting can’t be removed, brushing tannic acid powder into it, then later vacuuming, also helps to neutralize some allergens.

A Shot in the Arm

Immunotherapy is an option for some people for whom avoidance measures aren’t effective or prove impossible. (One of Davidson’s patients, a veterinary assistant, turned to allergy shots when wearing a mask and antihistamines could not eliminate all of her symptoms.)

Doctors give the desensitizing injections as a series of increasingly higher doses of the problematic animal’s protein, and the treatment can take up to five years. Davidson says these vaccines are more than 80 per cent effective in significantly reducing symptoms.

There are risks, however, ranging from minor swelling and irritation at the injection site to anaphylactic reaction. (Davidson estimates there are three to six deaths a year in the U.S. from all allergy shots, with those with poorly controlled asthma at a higher risk.)

Safer Pets

What is a good pet for those who duck for cover when the fur and feathers fly? “The textbook answer would be to get a fish or a reptile,” Davidson said, although he suggests “doing an audition” with a pet in your home for two or three days if you’re unsure how you’ll react. Just make sure you can return the pet.